What are the applicable regulations and guidance to increase the airplane gross weight?
a. Many changes may cause an increase in the airplane gross weight. In many cases, due to changes in the operational requirements of an owner/operator, the need arises to modify and substantiate the structure for an increase in maximum takeoff weight, in maximum landing weight, or in maximum zero fuel weight. b. An increase in maximum gross weight is in general a large effort, as it requires a complete review of all aspects of the aircraft design. When an airplane is initially designed, the manufacturer determines the gross weight through a process of compromise with the desired performance features. Once the gross weight is fixed, the details of the aircraft are designed around that weight. This means that the basic loads for the aircraft are determined using that weight, then the control surfaces and wing area are sized for those loads, and the size of the primary structure is determined using the same loads. Most manufacturers over estimate the weight by a small percentage to allow
